ᐅ Evaluation of Solar Power System Proposal with Battery Storage

kati1337 schrieb:

But at most the dirty electricity. It is likely that people who want to invest money in photovoltaic systems and storage are not only aiming to save money but also focusing on clean energy, and therefore would not buy non-renewable electricity.
If you care about genuine renewable electricity without certificate trading schemes, you’re typically looking at prices starting around 40 cents per kilowatt-hour.

Well, here we go again with the emotions when it comes to electricity.
People prefer to install a large lithium battery and call it environmental protection...

Looking at it realistically, at present, whenever you use green electricity, someone else cannot use that same amount and has to consume “dirty” electricity instead.
This is true whether it’s through certificates, other “authenticity” guarantees, or your storage system.

RotorMotor schrieb:

Realistically speaking, whenever you use green electricity, someone else can’t use it and has to rely on "dirty" electricity instead.

However, if more people demand green electricity and fewer people use dirty electricity, this supports the energy transition in the long run. That’s how the market works. If no one wants the dirty energy anymore, there’s no need to produce as much of it.
It’s similar to all the veggie and vegan products in discount stores. While conservatives are still arguing over whether vegan schnitzel should really be called schnitzel because it might confuse consumers who have been drinking scouring milk for decades, vegan products are increasingly taking up shelf space in discount stores and gradually pushing conventional products out of the range. This happens because there is demand for them. People don’t care what it’s called; they just want to buy it.

KarstenausNRW schrieb:

100% green electricity currently available for at least 24.66 cents. Contract signed two weeks ago. Even from the municipal utility and not some paper company.

Not here. I signed a contract at the beginning of September; the cheapest reliable option was Vattenfall at 29.x cents with a base fee of €12.99 (about $14.00). Others were slightly cheaper but generally came with higher base fees. So starting from 30 cents is reasonable. It is also labeled as green electricity. Whether it’s truly green or not doesn’t concern me here. Over the course of the year, I definitely feed significantly more genuine green electricity into the grid than I draw from it.

Good evening! Thank you very much for your really helpful comments and the example calculations.
If you also consider that with current interest rates you will pay around €1000 (approximately $1100) in interest over the next 10 years, the calculation worsens further. Since we are therefore looking at an even longer payback period than the calculated 12 to 19 years, and because, contrary to some opinions, I have little emotional attachment to the purchase, I will, based on the current situation, decide against a battery storage system. Additionally, I have roughly compiled the household’s evening and nighttime consumption, and I am probably not the right candidate here because I "live" too much during daylight hours ;-)
Even if the battery lasts 5 years longer than the payback period, this would only result in a theoretical gain of €1650 (approximately $1800) over 150 cycles, so not even a thousand euros if you factor in the interest. For me, this is not a worthwhile investment, especially since if it causes problems after 11 to 12 years, I might end up spending a similar amount again.
The question now is: would the photovoltaic system with 11.9 kWp without storage still be the right choice, or should I adjust the capacity up or down in some way?

Best regards

As much as the roof can accommodate. Up to a 25° roof pitch, even the north side can be practical.

Tolentino schrieb:

As much as the roof allows. Up to a 25° roof pitch, even the north side can be viable.

Hmm, okay, is that really the case? It feels like it’s less cost-effective if I produce too much and feed in for a low price. The panels cost money as well...
The roof pitch is 30° (86°F). The roof surfaces face southeast and northwest.